CGroup API files: make CGROUP_DEBUG default to off
[linux-2.6-block.git] / init / Kconfig
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1config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
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9config DEFCONFIG_LIST
10 string
b2670eac 11 depends on !UML
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12 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
16 default "arch/$ARCH/defconfig"
17
ff0cfc66 18menu "General setup"
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19
20config EXPERIMENTAL
21 bool "Prompt for development and/or incomplete code/drivers"
22 ---help---
23 Some of the various things that Linux supports (such as network
24 drivers, file systems, network protocols, etc.) can be in a state
25 of development where the functionality, stability, or the level of
26 testing is not yet high enough for general use. This is usually
27 known as the "alpha-test" phase among developers. If a feature is
28 currently in alpha-test, then the developers usually discourage
29 uninformed widespread use of this feature by the general public to
30 avoid "Why doesn't this work?" type mail messages. However, active
31 testing and use of these systems is welcomed. Just be aware that it
32 may not meet the normal level of reliability or it may fail to work
33 in some special cases. Detailed bug reports from people familiar
34 with the kernel internals are usually welcomed by the developers
35 (before submitting bug reports, please read the documents
36 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
37 <file:Documentation/BUG-HUNTING>, and
38 <file:Documentation/oops-tracing.txt> in the kernel source).
39
40 This option will also make obsoleted drivers available. These are
41 drivers that have been replaced by something else, and/or are
42 scheduled to be removed in a future kernel release.
43
44 Unless you intend to help test and develop a feature or driver that
45 falls into this category, or you have a situation that requires
46 using these features, you should probably say N here, which will
47 cause the configurator to present you with fewer choices. If
48 you say Y here, you will be offered the choice of using features or
49 drivers that are currently considered to be in the alpha-test phase.
50
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51config BROKEN
52 bool
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53
54config BROKEN_ON_SMP
55 bool
56 depends on BROKEN || !SMP
57 default y
58
59config LOCK_KERNEL
60 bool
61 depends on SMP || PREEMPT
62 default y
63
64config INIT_ENV_ARG_LIMIT
65 int
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66 default 32 if !UML
67 default 128 if UML
1da177e4 68 help
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69 Maximum of each of the number of arguments and environment
70 variables passed to init from the kernel command line.
1da177e4 71
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72
73config LOCALVERSION
74 string "Local version - append to kernel release"
75 help
76 Append an extra string to the end of your kernel version.
77 This will show up when you type uname, for example.
78 The string you set here will be appended after the contents of
79 any files with a filename matching localversion* in your
80 object and source tree, in that order. Your total string can
81 be a maximum of 64 characters.
82
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83config LOCALVERSION_AUTO
84 bool "Automatically append version information to the version string"
85 default y
86 help
87 This will try to automatically determine if the current tree is a
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88 release tree by looking for git tags that belong to the current
89 top of tree revision.
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90
91 A string of the format -gxxxxxxxx will be added to the localversion
6e5a5420 92 if a git-based tree is found. The string generated by this will be
aaebf433 93 appended after any matching localversion* files, and after the value
6e5a5420 94 set in CONFIG_LOCALVERSION.
aaebf433 95
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96 (The actual string used here is the first eight characters produced
97 by running the command:
98
99 $ git rev-parse --verify HEAD
100
101 which is done within the script "scripts/setlocalversion".)
aaebf433 102
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103config SWAP
104 bool "Support for paging of anonymous memory (swap)"
9361401e 105 depends on MMU && BLOCK
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106 default y
107 help
108 This option allows you to choose whether you want to have support
92c3504e 109 for so called swap devices or swap files in your kernel that are
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110 used to provide more virtual memory than the actual RAM present
111 in your computer. If unsure say Y.
112
113config SYSVIPC
114 bool "System V IPC"
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115 ---help---
116 Inter Process Communication is a suite of library functions and
117 system calls which let processes (running programs) synchronize and
118 exchange information. It is generally considered to be a good thing,
119 and some programs won't run unless you say Y here. In particular, if
120 you want to run the DOS emulator dosemu under Linux (read the
121 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
122 you'll need to say Y here.
123
124 You can find documentation about IPC with "info ipc" and also in
125 section 6.4 of the Linux Programmer's Guide, available from
126 <http://www.tldp.org/guides.html>.
127
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128config SYSVIPC_SYSCTL
129 bool
130 depends on SYSVIPC
131 depends on SYSCTL
132 default y
133
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134config POSIX_MQUEUE
135 bool "POSIX Message Queues"
136 depends on NET && EXPERIMENTAL
137 ---help---
138 POSIX variant of message queues is a part of IPC. In POSIX message
139 queues every message has a priority which decides about succession
140 of receiving it by a process. If you want to compile and run
141 programs written e.g. for Solaris with use of its POSIX message
b0e37650 142 queues (functions mq_*) say Y here.
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143
144 POSIX message queues are visible as a filesystem called 'mqueue'
145 and can be mounted somewhere if you want to do filesystem
146 operations on message queues.
147
148 If unsure, say Y.
149
150config BSD_PROCESS_ACCT
151 bool "BSD Process Accounting"
152 help
153 If you say Y here, a user level program will be able to instruct the
154 kernel (via a special system call) to write process accounting
155 information to a file: whenever a process exits, information about
156 that process will be appended to the file by the kernel. The
157 information includes things such as creation time, owning user,
158 command name, memory usage, controlling terminal etc. (the complete
159 list is in the struct acct in <file:include/linux/acct.h>). It is
160 up to the user level program to do useful things with this
161 information. This is generally a good idea, so say Y.
162
163config BSD_PROCESS_ACCT_V3
164 bool "BSD Process Accounting version 3 file format"
165 depends on BSD_PROCESS_ACCT
166 default n
167 help
168 If you say Y here, the process accounting information is written
169 in a new file format that also logs the process IDs of each
170 process and it's parent. Note that this file format is incompatible
171 with previous v0/v1/v2 file formats, so you will need updated tools
172 for processing it. A preliminary version of these tools is available
173 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
174
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175config TASKSTATS
176 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
177 depends on NET
178 default n
179 help
180 Export selected statistics for tasks/processes through the
181 generic netlink interface. Unlike BSD process accounting, the
182 statistics are available during the lifetime of tasks/processes as
183 responses to commands. Like BSD accounting, they are sent to user
184 space on task exit.
185
186 Say N if unsure.
187
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188config TASK_DELAY_ACCT
189 bool "Enable per-task delay accounting (EXPERIMENTAL)"
6f44993f 190 depends on TASKSTATS
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191 help
192 Collect information on time spent by a task waiting for system
193 resources like cpu, synchronous block I/O completion and swapping
194 in pages. Such statistics can help in setting a task's priorities
195 relative to other tasks for cpu, io, rss limits etc.
196
197 Say N if unsure.
198
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199config TASK_XACCT
200 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
201 depends on TASKSTATS
202 help
203 Collect extended task accounting data and send the data
204 to userland for processing over the taskstats interface.
205
206 Say N if unsure.
207
208config TASK_IO_ACCOUNTING
209 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
210 depends on TASK_XACCT
211 help
212 Collect information on the number of bytes of storage I/O which this
213 task has caused.
214
215 Say N if unsure.
216
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217config AUDIT
218 bool "Auditing support"
804a6a49 219 depends on NET
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220 help
221 Enable auditing infrastructure that can be used with another
222 kernel subsystem, such as SELinux (which requires this for
223 logging of avc messages output). Does not do system-call
224 auditing without CONFIG_AUDITSYSCALL.
225
226config AUDITSYSCALL
227 bool "Enable system-call auditing support"
1322b9de 228 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
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229 default y if SECURITY_SELINUX
230 help
231 Enable low-overhead system-call auditing infrastructure that
232 can be used independently or with another kernel subsystem,
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233 such as SELinux. To use audit's filesystem watch feature, please
234 ensure that INOTIFY is configured.
1da177e4 235
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236config AUDIT_TREE
237 def_bool y
238 depends on AUDITSYSCALL && INOTIFY
239
1da177e4 240config IKCONFIG
f2443ab6 241 tristate "Kernel .config support"
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242 ---help---
243 This option enables the complete Linux kernel ".config" file
244 contents to be saved in the kernel. It provides documentation
245 of which kernel options are used in a running kernel or in an
246 on-disk kernel. This information can be extracted from the kernel
247 image file with the script scripts/extract-ikconfig and used as
248 input to rebuild the current kernel or to build another kernel.
249 It can also be extracted from a running kernel by reading
250 /proc/config.gz if enabled (below).
251
252config IKCONFIG_PROC
253 bool "Enable access to .config through /proc/config.gz"
254 depends on IKCONFIG && PROC_FS
255 ---help---
256 This option enables access to the kernel configuration file
257 through /proc/config.gz.
258
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259config LOG_BUF_SHIFT
260 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
261 range 12 21
f17a32e9 262 default 17
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263 help
264 Select kernel log buffer size as a power of 2.
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265 Examples:
266 17 => 128 KB
267 16 => 64 KB
268 15 => 32 KB
269 14 => 16 KB
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270 13 => 8 KB
271 12 => 4 KB
272
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273config CGROUPS
274 bool "Control Group support"
275 help
276 This option will let you use process cgroup subsystems
277 such as Cpusets
278
279 Say N if unsure.
280
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281config CGROUP_DEBUG
282 bool "Example debug cgroup subsystem"
283 depends on CGROUPS
418d7d87 284 default n
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285 help
286 This option enables a simple cgroup subsystem that
287 exports useful debugging information about the cgroups
288 framework
289
290 Say N if unsure
291
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292config CGROUP_NS
293 bool "Namespace cgroup subsystem"
294 depends on CGROUPS
295 help
296 Provides a simple namespace cgroup subsystem to
297 provide hierarchical naming of sets of namespaces,
298 for instance virtual servers and checkpoint/restart
299 jobs.
300
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301config CPUSETS
302 bool "Cpuset support"
8793d854 303 depends on SMP && CGROUPS
1da177e4 304 help
d9fd8a6d 305 This option will let you create and manage CPUSETs which
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306 allow dynamically partitioning a system into sets of CPUs and
307 Memory Nodes and assigning tasks to run only within those sets.
308 This is primarily useful on large SMP or NUMA systems.
309
310 Say N if unsure.
311
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312config GROUP_SCHED
313 bool "Group CPU scheduler"
de8d585a 314 default y
29f59db3 315 help
fb615581 316 This feature lets CPU scheduler recognize task groups and control CPU
9b5b7751 317 bandwidth allocation to such task groups.
29f59db3 318
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319config FAIR_GROUP_SCHED
320 bool "Group scheduling for SCHED_OTHER"
321 depends on GROUP_SCHED
322 default y
323
324config RT_GROUP_SCHED
325 bool "Group scheduling for SCHED_RR/FIFO"
326 depends on EXPERIMENTAL
327 depends on GROUP_SCHED
328 default n
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329 help
330 This feature lets you explicitly allocate real CPU bandwidth
331 to users or control groups (depending on the "Basis for grouping tasks"
332 setting below. If enabled, it will also make it impossible to
333 schedule realtime tasks for non-root users until you allocate
334 realtime bandwidth for them.
335 See Documentation/sched-rt-group.txt for more information.
052f1dc7 336
24e377a8 337choice
052f1dc7 338 depends on GROUP_SCHED
24e377a8 339 prompt "Basis for grouping tasks"
052f1dc7 340 default USER_SCHED
24e377a8 341
052f1dc7 342config USER_SCHED
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343 bool "user id"
344 help
345 This option will choose userid as the basis for grouping
346 tasks, thus providing equal CPU bandwidth to each user.
24e377a8 347
052f1dc7 348config CGROUP_SCHED
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349 bool "Control groups"
350 depends on CGROUPS
351 help
352 This option allows you to create arbitrary task groups
353 using the "cgroup" pseudo filesystem and control
354 the cpu bandwidth allocated to each such task group.
355 Refer to Documentation/cgroups.txt for more information
356 on "cgroup" pseudo filesystem.
357
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358endchoice
359
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360config CGROUP_CPUACCT
361 bool "Simple CPU accounting cgroup subsystem"
362 depends on CGROUPS
363 help
364 Provides a simple Resource Controller for monitoring the
365 total CPU consumed by the tasks in a cgroup
366
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367config RESOURCE_COUNTERS
368 bool "Resource counters"
369 help
370 This option enables controller independent resource accounting
371 infrastructure that works with cgroups
372 depends on CGROUPS
373
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374config CGROUP_MEM_RES_CTLR
375 bool "Memory Resource Controller for Control Groups"
376 depends on CGROUPS && RESOURCE_COUNTERS
377 help
378 Provides a memory resource controller that manages both page cache and
379 RSS memory.
380
381 Note that setting this option increases fixed memory overhead
382 associated with each page of memory in the system by 4/8 bytes
383 and also increases cache misses because struct page on many 64bit
384 systems will not fit into a single cache line anymore.
385
386 Only enable when you're ok with these trade offs and really
387 sure you need the memory resource controller.
388
88a22c98 389config SYSFS_DEPRECATED
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390 bool
391
392config SYSFS_DEPRECATED_V2
88a22c98 393 bool "Create deprecated sysfs files"
9148fe87 394 depends on SYSFS
88a22c98 395 default y
d47846c5 396 select SYSFS_DEPRECATED
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397 help
398 This option creates deprecated symlinks such as the
399 "device"-link, the <subsystem>:<name>-link, and the
400 "bus"-link. It may also add deprecated key in the
401 uevent environment.
402 None of these features or values should be used today, as
403 they export driver core implementation details to userspace
404 or export properties which can't be kept stable across kernel
405 releases.
406
407 If enabled, this option will also move any device structures
3dde6ad8 408 that belong to a class, back into the /sys/class hierarchy, in
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409 order to support older versions of udev and some userspace
410 programs.
88a22c98 411
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412 If you are using a distro with the most recent userspace
413 packages, it should be safe to say N here.
88a22c98 414
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415config PROC_PID_CPUSET
416 bool "Include legacy /proc/<pid>/cpuset file"
417 depends on CPUSETS
418 default y
419
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420config RELAY
421 bool "Kernel->user space relay support (formerly relayfs)"
422 help
423 This option enables support for relay interface support in
424 certain file systems (such as debugfs).
425 It is designed to provide an efficient mechanism for tools and
426 facilities to relay large amounts of data from kernel space to
427 user space.
428
429 If unsure, say N.
430
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431config NAMESPACES
432 bool "Namespaces support" if EMBEDDED
433 default !EMBEDDED
434 help
435 Provides the way to make tasks work with different objects using
436 the same id. For example same IPC id may refer to different objects
437 or same user id or pid may refer to different tasks when used in
438 different namespaces.
439
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440config UTS_NS
441 bool "UTS namespace"
442 depends on NAMESPACES
443 help
444 In this namespace tasks see different info provided with the
445 uname() system call
446
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447config IPC_NS
448 bool "IPC namespace"
449 depends on NAMESPACES && SYSVIPC
450 help
451 In this namespace tasks work with IPC ids which correspond to
452 different IPC objects in different namespaces
453
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454config USER_NS
455 bool "User namespace (EXPERIMENTAL)"
456 depends on NAMESPACES && EXPERIMENTAL
457 help
458 This allows containers, i.e. vservers, to use user namespaces
459 to provide different user info for different servers.
460 If unsure, say N.
461
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462config PID_NS
463 bool "PID Namespaces (EXPERIMENTAL)"
464 default n
465 depends on NAMESPACES && EXPERIMENTAL
466 help
467 Suport process id namespaces. This allows having multiple
468 process with the same pid as long as they are in different
469 pid namespaces. This is a building block of containers.
470
471 Unless you want to work with an experimental feature
472 say N here.
473
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474config BLK_DEV_INITRD
475 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
476 depends on BROKEN || !FRV
477 help
478 The initial RAM filesystem is a ramfs which is loaded by the
479 boot loader (loadlin or lilo) and that is mounted as root
480 before the normal boot procedure. It is typically used to
481 load modules needed to mount the "real" root file system,
482 etc. See <file:Documentation/initrd.txt> for details.
483
484 If RAM disk support (BLK_DEV_RAM) is also included, this
485 also enables initial RAM disk (initrd) support and adds
486 15 Kbytes (more on some other architectures) to the kernel size.
487
488 If unsure say Y.
489
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490if BLK_DEV_INITRD
491
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492source "usr/Kconfig"
493
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494endif
495
c45b4f1f 496config CC_OPTIMIZE_FOR_SIZE
96fffeb4 497 bool "Optimize for size"
c45b4f1f 498 default y
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499 help
500 Enabling this option will pass "-Os" instead of "-O2" to gcc
501 resulting in a smaller kernel.
502
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503 If unsure, say N.
504
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505config SYSCTL
506 bool
507
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508menuconfig EMBEDDED
509 bool "Configure standard kernel features (for small systems)"
510 help
511 This option allows certain base kernel options and settings
512 to be disabled or tweaked. This is for specialized
513 environments which can tolerate a "non-standard" kernel.
514 Only use this if you really know what you are doing.
515
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516config UID16
517 bool "Enable 16-bit UID system calls" if EMBEDDED
09337f50 518 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
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519 default y
520 help
521 This enables the legacy 16-bit UID syscall wrappers.
522
b89a8171 523config SYSCTL_SYSCALL
0847062a 524 bool "Sysctl syscall support" if EMBEDDED
13bb7e37 525 default y
b89a8171 526 select SYSCTL
ae81f9e3 527 ---help---
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528 sys_sysctl uses binary paths that have been found challenging
529 to properly maintain and use. The interface in /proc/sys
530 using paths with ascii names is now the primary path to this
531 information.
b89a8171 532
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533 Almost nothing using the binary sysctl interface so if you are
534 trying to save some space it is probably safe to disable this,
535 making your kernel marginally smaller.
b89a8171 536
13bb7e37 537 If unsure say Y here.
ae81f9e3 538
1da177e4 539config KALLSYMS
979c6a1e 540 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
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541 default y
542 help
543 Say Y here to let the kernel print out symbolic crash information and
544 symbolic stack backtraces. This increases the size of the kernel
545 somewhat, as all symbols have to be loaded into the kernel image.
546
547config KALLSYMS_ALL
548 bool "Include all symbols in kallsyms"
549 depends on DEBUG_KERNEL && KALLSYMS
550 help
551 Normally kallsyms only contains the symbols of functions, for nicer
552 OOPS messages. Some debuggers can use kallsyms for other
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553 symbols too: say Y here to include all symbols, if you need them
554 and you don't care about adding 300k to the size of your kernel.
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555
556 Say N.
557
558config KALLSYMS_EXTRA_PASS
559 bool "Do an extra kallsyms pass"
560 depends on KALLSYMS
561 help
562 If kallsyms is not working correctly, the build will fail with
563 inconsistent kallsyms data. If that occurs, log a bug report and
564 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
565 Always say N here unless you find a bug in kallsyms, which must be
566 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
567 you wait for kallsyms to be fixed.
568
d59745ce 569
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570config HOTPLUG
571 bool "Support for hot-pluggable devices" if EMBEDDED
572 default y
573 help
574 This option is provided for the case where no hotplug or uevent
575 capabilities is wanted by the kernel. You should only consider
576 disabling this option for embedded systems that do not use modules, a
577 dynamic /dev tree, or dynamic device discovery. Just say Y.
578
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579config PRINTK
580 default y
581 bool "Enable support for printk" if EMBEDDED
582 help
583 This option enables normal printk support. Removing it
584 eliminates most of the message strings from the kernel image
585 and makes the kernel more or less silent. As this makes it
586 very difficult to diagnose system problems, saying N here is
587 strongly discouraged.
588
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589config BUG
590 bool "BUG() support" if EMBEDDED
591 default y
592 help
593 Disabling this option eliminates support for BUG and WARN, reducing
594 the size of your kernel image and potentially quietly ignoring
595 numerous fatal conditions. You should only consider disabling this
596 option for embedded systems with no facilities for reporting errors.
597 Just say Y.
598
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599config ELF_CORE
600 default y
601 bool "Enable ELF core dumps" if EMBEDDED
602 help
603 Enable support for generating core dumps. Disabling saves about 4k.
604
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605config COMPAT_BRK
606 bool "Disable heap randomization"
607 default y
608 help
609 Randomizing heap placement makes heap exploits harder, but it
610 also breaks ancient binaries (including anything libc5 based).
611 This option changes the bootup default to heap randomization
612 disabled, and can be overriden runtime by setting
613 /proc/sys/kernel/randomize_va_space to 2.
614
166124fd 615 On non-ancient distros (post-2000 ones) N is usually a safe choice.
32a93233 616
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617config BASE_FULL
618 default y
619 bool "Enable full-sized data structures for core" if EMBEDDED
620 help
621 Disabling this option reduces the size of miscellaneous core
622 kernel data structures. This saves memory on small machines,
623 but may reduce performance.
624
625config FUTEX
626 bool "Enable futex support" if EMBEDDED
627 default y
23f78d4a 628 select RT_MUTEXES
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629 help
630 Disabling this option will cause the kernel to be built without
631 support for "fast userspace mutexes". The resulting kernel may not
632 run glibc-based applications correctly.
633
5dc8bf81 634config ANON_INODES
448e3cee 635 bool
5dc8bf81 636
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637config EPOLL
638 bool "Enable eventpoll support" if EMBEDDED
639 default y
448e3cee 640 select ANON_INODES
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641 help
642 Disabling this option will cause the kernel to be built without
643 support for epoll family of system calls.
644
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645config SIGNALFD
646 bool "Enable signalfd() system call" if EMBEDDED
448e3cee 647 select ANON_INODES
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648 default y
649 help
650 Enable the signalfd() system call that allows to receive signals
651 on a file descriptor.
652
653 If unsure, say Y.
654
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655config TIMERFD
656 bool "Enable timerfd() system call" if EMBEDDED
448e3cee 657 select ANON_INODES
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658 default y
659 help
660 Enable the timerfd() system call that allows to receive timer
661 events on a file descriptor.
662
663 If unsure, say Y.
664
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665config EVENTFD
666 bool "Enable eventfd() system call" if EMBEDDED
448e3cee 667 select ANON_INODES
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668 default y
669 help
670 Enable the eventfd() system call that allows to receive both
671 kernel notification (ie. KAIO) or userspace notifications.
672
673 If unsure, say Y.
674
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675config SHMEM
676 bool "Use full shmem filesystem" if EMBEDDED
677 default y
678 depends on MMU
679 help
680 The shmem is an internal filesystem used to manage shared memory.
681 It is backed by swap and manages resource limits. It is also exported
682 to userspace as tmpfs if TMPFS is enabled. Disabling this
683 option replaces shmem and tmpfs with the much simpler ramfs code,
684 which may be appropriate on small systems without swap.
685
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686config VM_EVENT_COUNTERS
687 default y
688 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
689 help
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690 VM event counters are needed for event counts to be shown.
691 This option allows the disabling of the VM event counters
692 on EMBEDDED systems. /proc/vmstat will only show page counts
693 if VM event counters are disabled.
f8891e5e 694
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695config SLUB_DEBUG
696 default y
697 bool "Enable SLUB debugging support" if EMBEDDED
d4751a27 698 depends on SLUB
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699 help
700 SLUB has extensive debug support features. Disabling these can
701 result in significant savings in code size. This also disables
702 SLUB sysfs support. /sys/slab will not exist and there will be
703 no support for cache validation etc.
704
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705choice
706 prompt "Choose SLAB allocator"
a0acd820 707 default SLUB
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708 help
709 This option allows to select a slab allocator.
710
711config SLAB
712 bool "SLAB"
713 help
714 The regular slab allocator that is established and known to work
34013886 715 well in all environments. It organizes cache hot objects in
81819f0f 716 per cpu and per node queues. SLAB is the default choice for
34013886 717 a slab allocator.
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718
719config SLUB
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720 bool "SLUB (Unqueued Allocator)"
721 help
722 SLUB is a slab allocator that minimizes cache line usage
723 instead of managing queues of cached objects (SLAB approach).
724 Per cpu caching is realized using slabs of objects instead
725 of queues of objects. SLUB can use memory efficiently
34013886 726 and has enhanced diagnostics.
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727
728config SLOB
84a01c2f 729 depends on EMBEDDED
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730 bool "SLOB (Simple Allocator)"
731 help
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732 SLOB replaces the stock allocator with a drastically simpler
733 allocator. SLOB is generally more space efficient but
734 does not perform as well on large systems.
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735
736endchoice
737
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738config PROFILING
739 bool "Profiling support (EXPERIMENTAL)"
740 help
741 Say Y here to enable the extended profiling support mechanisms used
742 by profilers such as OProfile.
743
744config MARKERS
745 bool "Activate markers"
746 help
747 Place an empty function call at each marker site. Can be
748 dynamically changed for a probe function.
749
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750source "arch/Kconfig"
751
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752config PROC_PAGE_MONITOR
753 default y
754 depends on PROC_FS && MMU
755 bool "Enable /proc page monitoring" if EMBEDDED
756 help
757 Various /proc files exist to monitor process memory utilization:
758 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
759 /proc/kpagecount, and /proc/kpageflags. Disabling these
760 interfaces will reduce the size of the kernel by approximately 4kb.
761
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762endmenu # General setup
763
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764config SLABINFO
765 bool
766 depends on PROC_FS
0f389ec6 767 depends on SLAB || SLUB_DEBUG
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768 default y
769
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770config RT_MUTEXES
771 boolean
772 select PLIST
773
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774config TINY_SHMEM
775 default !SHMEM
776 bool
777
778config BASE_SMALL
779 int
780 default 0 if BASE_FULL
781 default 1 if !BASE_FULL
782
66da5733 783menuconfig MODULES
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784 bool "Enable loadable module support"
785 help
786 Kernel modules are small pieces of compiled code which can
787 be inserted in the running kernel, rather than being
788 permanently built into the kernel. You use the "modprobe"
789 tool to add (and sometimes remove) them. If you say Y here,
790 many parts of the kernel can be built as modules (by
791 answering M instead of Y where indicated): this is most
792 useful for infrequently used options which are not required
793 for booting. For more information, see the man pages for
794 modprobe, lsmod, modinfo, insmod and rmmod.
795
796 If you say Y here, you will need to run "make
797 modules_install" to put the modules under /lib/modules/
798 where modprobe can find them (you may need to be root to do
799 this).
800
801 If unsure, say Y.
802
803config MODULE_UNLOAD
804 bool "Module unloading"
805 depends on MODULES
806 help
807 Without this option you will not be able to unload any
808 modules (note that some modules may not be unloadable
809 anyway), which makes your kernel slightly smaller and
810 simpler. If unsure, say Y.
811
812config MODULE_FORCE_UNLOAD
813 bool "Forced module unloading"
814 depends on MODULE_UNLOAD && EXPERIMENTAL
815 help
816 This option allows you to force a module to unload, even if the
817 kernel believes it is unsafe: the kernel will remove the module
818 without waiting for anyone to stop using it (using the -f option to
819 rmmod). This is mainly for kernel developers and desperate users.
820 If unsure, say N.
821
1da177e4 822config MODVERSIONS
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823 bool "Module versioning support"
824 depends on MODULES
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825 help
826 Usually, you have to use modules compiled with your kernel.
827 Saying Y here makes it sometimes possible to use modules
828 compiled for different kernels, by adding enough information
829 to the modules to (hopefully) spot any changes which would
830 make them incompatible with the kernel you are running. If
831 unsure, say N.
832
833config MODULE_SRCVERSION_ALL
834 bool "Source checksum for all modules"
835 depends on MODULES
836 help
837 Modules which contain a MODULE_VERSION get an extra "srcversion"
838 field inserted into their modinfo section, which contains a
839 sum of the source files which made it. This helps maintainers
840 see exactly which source was used to build a module (since
841 others sometimes change the module source without updating
842 the version). With this option, such a "srcversion" field
843 will be created for all modules. If unsure, say N.
844
845config KMOD
846 bool "Automatic kernel module loading"
847 depends on MODULES
848 help
849 Normally when you have selected some parts of the kernel to
850 be created as kernel modules, you must load them (using the
851 "modprobe" command) before you can use them. If you say Y
852 here, some parts of the kernel will be able to load modules
853 automatically: when a part of the kernel needs a module, it
854 runs modprobe with the appropriate arguments, thereby
855 loading the module if it is available. If unsure, say Y.
856
857config STOP_MACHINE
858 bool
859 default y
860 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
861 help
862 Need stop_machine() primitive.
3a65dfe8 863
3a65dfe8 864source "block/Kconfig"
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865
866config PREEMPT_NOTIFIERS
867 bool
e260be67 868
e260be67 869config CLASSIC_RCU
21bbb39c 870 def_bool !PREEMPT_RCU
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871 help
872 This option selects the classic RCU implementation that is
873 designed for best read-side performance on non-realtime
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874 systems. Classic RCU is the default. Note that the
875 PREEMPT_RCU symbol is used to select/deselect this option.